Having appropriate gear swaps, using JAs when they're up -instead of using berserk once every 20 minutes, knowing how to reduce JA delay as much as possible, knowing what to merit, being quick to engage, knowing when to use temp items if you have them/using them correctly, being aware of when to use PDT/MDT sets to avoid dieing, knowing when to not ws things like glavoid so you dont heal it, knowing when to run away from stuff you're fighting, the ability to position yourself correctly so you auto target mob#2 after #1 dies, knowing how damage is calculated and making the most out of the gear you have access to, etc, etc, etc.........
I could go on, but I think you get the point.
Another mark of good warriors is that they have skilled up every weapon so they get all the procs they can get, which takes a lot of dedication and its very time consuming, even if using retaliation, mandies, and an alt WHM to heal yourself with. So I would say dedication and a willingness to do crappy busy work for weeks is important to being a good WAR also.